Objective: To report a case of leukocytoclastic vasculitis associated with insulin aspart therapy.
Case summary: A 56-year-old man was admitted to the Department of Endocrinology because of a poorly controlled Type 2 diabetes. In an attempt to reach a tight blood glucose control, an intensive diabetes management consisting of one evening dose of intermediate-acting NPH insulin and three preprandial doses of short-acting insulin aspart was introduced. Two weeks following insulin aspart introduction the patient developed palpable purpura on distal parts of the upper and lower limbs. Four days after the onset of purpura, a skin biopsy was preformed. Histological examination showed vasculitis with perivascular infiltrates of lymphocytes and erythrocyte extravasation. Direct immunofluorescence was negative. On the day the purpuric eruptions appeared, insulin aspart was substituted with regular human insulin. All skin lesions disappeared spontaneously within 8 days. Insulin aspart was not re-administered.
Discussion: Other possible causes of vasculitis in this case were excluded by diagnostic tests. The temporal relationship between the insulin aspart administration and the occurrence of purpura, with no further episodes of skin eruptions after discontinuation of the drug, support the hypothesis of an insulin aspart caused vasculitis. Based on the Naranjo's algorithm, the adverse drug reaction could be considered possible.
Conclusion: Clinicians should be aware of the possibility of leukocytoclastic vasculitis occurring during insulin aspart treatment.